The present invention relates to an ejector device for vacuum drying, and particularly to an ejector device to cause negative pressure by high-speed air jet for rapid drying of the environmental space under vacuum.
There are many places requiring indoor drying operation. Particularly, however, the sterilizing devices used for sterilizing and disinfecting medical articles in hospitals or the like require drying process as an indispensable essential element, because in the case of failure in drying operation, the steam or moisture produced in the process of high pressure sterilization in the sterilizing device is entrained to sterilized articles, constituting a cause for propagation of other bacteria or infection when used as such.
Accordingly, conventional large-scale autoclaves are generally equipped with vacuum pumps for drying operation. The main reason for using vacuum pumps is to reduce the pressure dominant in the sterilizing chambers incorporated for sterilizing medical articles or the like. There are two reasons of generating a vacuum state by decreasing the pressure in a sterilizing chamber. The total vacuum process is composed of the pre-vacuum and post-vacuum processes. In the pre-vacuum process, the air or air layer in the chamber space is expelled out as the generated steam rises to penetrate and displace the air, as the air layer, a heat insulating layer, would otherwise inhibit the conductive heat transfer to thereby disfavor the sterilizing operation. In the subsequent post-vacuum process, the dry or superheated steam vapor originating from the moisture or water in the chamber can be discharged, as the temperature in the chamber is above the vaporization point or condensation point, which is low at this reduced prevailing pressure, so that a complete moisture removal or drying in the chamber can be realized. This is possible because the steam is continuously removed from the chamber by the vacuum pump.
In practice, however, most of vertical type autoclaves or the so-called top-table autoclaves are not provided with vacuum pumps, in contrast to the large scale autoclaves. The reason for this is that sterilizing devices become heavy for their size and the vacuum pumps should be further equipped with accessories like water supplying pipes and water draining pipes and moreover the pumps generate severe vibration and noise.
However, the top-table autoclaves have the advantage that they are more easily movable compared to the large-scale autoclave described above and can be put to use at any places where the electricity is available. Nevertheless, as the relevant vacuum pumps operate based on the suction of steam, the water is need. Thus, the installation of water supplying and draining pipes is essential, restricting free movement, so that the advantage of the top-table autoclaves mentioned above is cancelled out. Thus, sterilization of a top-table autoclave without a vacuum pump is conducted based on gravity mode, and thus there is caused the problem that drying should be performed during the drying process, with the door of the sterilizing chamber open.
The opening of the doors of sterilizing chambers during drying process is associated with the risk of bacteria or the like penetrating the inside of the sterilizing chambers to reduce the sterilization effect and furthermore to cause the users the inconvenience of opening and closing the door every individually.
Therefore, the object of the present invention is to provide an ejector device for vacuum drying, resolving the above-described drawbacks, which can generate a negative pressure by means of a high-speed air jet stream to evacuate the near-by space, so that the moisture of the wet articles positioned in that space may be rapidly vaporized under the surrounding reduced pressure to bring the articles to a complete dryness.
The above object is achieved according to an aspect of the invention by an ejector device for vacuum drying, comprising an ejector with at least a first and second passages for connecting the first and second chambers in mutual communication, the first and second chambers being arranged at the right angle to each other, wherein the ejector is adapted for vacuum-drying the inside of the second chamber by ejecting high-speed air toward the first chamber via the second passage from the first passage""s side opposite to the first chamber to induce a negative pressure in the first passage due to the change in kinetic energy so as to draw the stagnant air and steam existing in the second chamber into the inside of the first chamber.
Preferably, the vacuum drying ejector comprises a body formed, at the one ends of the first and second passages, with the first and second connecting sections for water-tight connection with the first and second chambers, the first and second passages being perpendicular to each other, and an air jet nozzle detachably connected to said body through screwing at the first passage""s end opposite to the first chamber, provided with the third passage for connection with an air pump, and provided with an air jet hole or channel to be in communication with the first and second passages, said air jet nozzle forming a gap between its front outer circumference and the wall of the first passage along the area beyond the position of the second passage.
Further, said air jet hole or channel is preferably formed tapered toward the front end of the air jet nozzle to result in the form of a cone frustum.